Internet Speed Spikes

[cpjitservices]

This one is baffling me now, we have Unjoined Domain PC's and when I go to speedtest.net and do a speed test I gt a nice smooth steady speed, but when I do it from a domain joined PC and do the same thing the speed spikes and it isnt as high speed, no long distances from the switch and everything is plugged into the same switch, the servers also spike.

 

Any Ideas ? I Have ruled out the switch and my DNS.

[3s-gtech]

Dodgy proxy settings being applied by GP?

[cpjitservices]

No but thanks I've figured it, new version of Sophos!!! I disabled on-access scanning and all is well